abc to dq0 transform is used frequently while making matlab models for machines?What is the advantage of using it over normal abc?
In this case, we can assume a perfect orientation of the frame dq, that is to say the axis d coincides with the rotor flux vector, therefore, the quadrature component of flux as well as its derivative will be cancelled.
this approach is very useful for the control needs (Vector control) since it allows the control of only one flux component (axis d) Instead of two components (axis d and q). Also, the electromagnetic torque equation will be simplified..
For the observer design need, we use (alfa,beta) presentation of the induction machine. the cause is that the statorique pulsation equals to zero (the same reasoning as the park frame) and so we are not obliged to estimate it thought the observer since it is not a variable state in the state model of IM.
I agree with Omar Naifar and simply to put it in one word the complexity of any calculations performed with abc can be reduced with dq transformation.
To reduce complexity of the system with dc values instead of ac values. but Park transformation have some disadvantages too like the PLL which causes the waveform to follow the grid voltage according to the angle. So, if there is any problem in PLL(phase Lock loop) then system might not work properly.
To sum up: it is much easier to design a controller for the dq model because you deal with DC values. So, you can use a regular PID with a dq model, which is not possible to apply directly on a regular ABC model.
In induction machine, it is possible to control torque with iqs and flux with ids independently. Besides, by controlling torque using iqs , we have a fast torque response.
Easier to control one reference frame in Dq0 i.e. direct axis, while abc is difficult to control.
Dq0 frame, allows your system to be controlled by one controller for only d axis while in abc frame it is difficult to program three controllers while co-relating them with their results and adds more complexity to system.
Furthermore, Dq0 frames are preferred for synchronous machines while alpha beta zero transform is preferred for induction machine.
The solution for flux and torque is difficult in mathematics using abc rotation reference frame, while it is much easier in dq frame.
i use park transformation in controlling grid connected three phase inverter
it is great since it transforms the control problem to two controllers and makes the calculation easier
Control of asymmetrical system is not possible in abc-frame. But can be done in dq-frame.
I agree with all the above answer.
To reduce complexity of the system and d axis components is non-zero and q & o are zero. The q axis is zero because of unity power factor.
important of all is that, with dq transformation the complexity of system is reduce and the most important thing is decoupling can be done by independently controlling flux and torque utilizing Idq and the transformation basically help in control part of motor drives but for the that rotor position is required for the efficient working with perfect PID controller
The following points briefly address your concerns about performing the abc-to-dqo transformation:
1. The fundamental reason to transform the three-phase instantaneous voltages and currents into the synchronously rotating reference dqo frame is to shrink the dimensions from 3 to 2 thereby making mathematical computations much easier. Secondly, it allows the system operator to independently control the active (d-axis) and reactive (q-axis) components of the currents.
2. Additionally, in the dqo-frame, the mutual inductance is constant. Thus, it allows the system operator to achieve the desired output as the inductance-dependent quantities are constant.
3. Furthermore, the various feedback controller including proportional-integral (PI) and proportional-integral-derivative (PID) practically offers an effective and reliable control solution when the quantities are DC (i.e., constant) in nature. On the contrary, if the input quantities applied to these feedback controllers are periodic or sinusoidal then the integrator (i.e., 1/S) term of these controllers typically fails to introduce the infinite gain. As a result, the steady-state error will not be forced to zero.
4. Most importantly, the dqo-coordinate system provides a significant leap in inverter/motor control by translating the three-phase abc-reference frame into the dqo-coordinate system. This transformation paves the way for an almost homogenous magnetic field across both axes (dq). As a result, independent control of both torque (Iq) and flux (Id) can be realized to address the challenge of the coupling effect encountered with the classical scaler control.
5. Notably, the mathematical paradigm of transitioning from abc to dq coordinates echoes a shift in mathematical coordinates, like transitioning from Cartesian to polar coordinates.
The main advantage of adc-to-dqo transformation is to operate the induction machine like a separate excitation DC machine, so the torque and flux can be separately controlled.
- Badges
- Science topic
- Similar topics
- Linguistics
- Composition Studies
- Publication